Ecosystems Infographic

Hodgson, Mary // The savanna life planner


The lack of tightly packed trees and subsequent domination of grasses that characterise savannas has traditionally been linked to human deforestation. However, recent research into the frequent grass fuelled fires has begun to answer questions on the origins of savannas. The purpose of this infographic is to aid GCSE Biology students learning about the importance of the savanna ecosystems and to warn against possible reforestation efforts in such open spaces.


In savanna ecosystems tree cover is sparse, allowing grasses to thrive and dominate. This lack of tree density that defines savannas has been traditionally linked to human deforestation.

Savannas have frequent grass fuelled fires. Trees unique to the savanna have large underground storage organs that enable them to survive the fires. These organs allow plants to rapidly resprout after the fire.

Sceintists have shown that most trees in fire-maintained African savannas can be traced back to between 2.5 and 6 million years ago. This suggests that savannas predate humans by millions of years.

Grassy biomes must remain as ancient ecosystems and not be replaced by forests due to a lack of knowledge of their origins.

Mary Hodgson

Mary will start her PhD in Lancaster in October, researching the individual and interactive effects of grazing, fire and climate change on savanna soil biology. Mary is passionate about the environment and likes to spend weekends running round the Lake District with her dogs.


Organisation: Lancaster University